Yeah, you'd think an 18" speaker cab was made for bass frequencies......but looking at the behringer website, that cab is -6db @ 42Hz.

That's not even very good down to low E.

I dunno......give it a try; maybe it'll sound better than it looks on paper. But if you're not happy with it, don't dismiss all 18's as useless - there's a lot of good ones, although they ain't generally very cheap. If you want to keep the price down, try the Yamaha mentioned earlier. Street price about $350 as I recall. It's not the best, but for the price it's very good.

Well, I could be wrong, but I don't get the impression that this fellow was looking to build his own cab.

Myself...I've got an 18" Kilomax in an 8 ft cabinet....Muy thick.

But it really seems that this cab size is just on the far side of convenient. Of course, I'm talking in the context of bass cabs.....

I've got a couple of old Cerwin-Vega front-loaded 18" cabs that are 6 cubic feet. Slot port, easy to adjust the cab tuning with some plywood. Planning on trying out some Adire Audio Maelstroms in 'em. Looks real good on paper, and while the size difference doesn't seem that much, they are quite a bit easier to live with.

I've heard lotsa good things about the Maelstrom, but only from the home theater fanatics, nothing (yet) from live sound - it seems this driver is just starting to see some use in PA applications. Adire has do-it-yourself plans on their website for an 18"+10" coaxial PA cab called a Hurricane. They've got measured frequency response curves that look very interesting.....

My full rig consists of an Epifani 210 and a JBL MP418S (single 18" in slot ported box). Short of an SPL Servodrive sub, there is no better way to get good LOUD bottom end than a good 18. But as noted previously, just because a speaker is 18" in diameter does not mean it goes really low.

I just came back from playing 4 days straight at a conference in a main room for about 200 people.

We were using a mackie 1801 - 18" active sub. For stage sound i was using the power stage of my swr workingman's 15.

the Sub was great to say the least. It filled out the entire room very easily with everything from my bass, to the drum's (kick and all) etc etc, with a fixed crossover at 120hz (i dont know why its so high in pa subs, as opposed to HT subs which are 80hz and lower)

in any case, i would higly recommend the mackie 1801, great sub, but way more expensive than the other subs in this thread, but you get what you pay for.

I only use them for outdoor gigs, and they definitely get the bass frequencies "out there" into the audience. Indoors, they'd be massive overkill. For indoors I use BagEnd S-15's and S-12's, the number varies according to the size of the room.